Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net Income Attributable to Union Carbide Corporation	$ 627	$ 1,055	$ 205
Other Comprehensive Income (Loss), Net of Tax
Cumulative translation adjustments	1	2	3
Pension and other postretirement benefit plans	(105)	43	(35)
Net other comprehensive income	(104)	45	(32)
Comprehensive Income Attributable to Union Carbide Corporation	$ 523	$ 1,100	$ 173